Abstract: A simplified bi-annular-shaped bearing with anti-play characteristics has an inner race, an outer race, at least one ring groove and a roller-shaped limiting set, The races can relatively rotate. The ring groove is configured on the periphery of the inner race or the inner ring surface of the outer race. The roller-shaped limiting set is configured on at least one position of the outer race or inner race, and comprises rigid balls, elastic supporting components and positioning members. The outer race or inner race is configured with a radial housing part to hold the roller-shaped limiting set. The elastic supporting component is to elastically push the rigid ball toward the end opening configured on the radial housing part, so that it will go into and contact against the ring groove.

Abstract: A SIC mechanical seal including a main body made of SIC materials. The main body includes a fixing portion and a pushed surface. The seal also includes a retainer including a shaft coupling seat, a push ring and an elastic part; of which the push ring is made of SIC material, and provided with a ring surface that's riveted to the pushed surface of the main body. The seal also includes at least an area of lower friction, set globally or locally onto either the pushed surface of the main body or the ring surface of the push ring. The friction of this area is less than that of the main body and the push ring. The area of lower friction is of a composite layer which is made of a mixture of SIC and carbon materials, or composed of multiple dents arranged at interval.